WASHINGTON — The nation's top intelligence official on Wednesday declassified three secret U.S. court opinions and other classified documents that reveal how the National Security Agency intercepted thousands of e-mails from Americans with no connection to terrorism.

Director of National Intelligence James Clapper authorized the release and the agency published the documents on a newly created Tumblr page dubbed IC on the Record.

The latest revelations come amid growing criticism from members of Congress and privacy groups about the NSA surveillance programs and charges that the agency has far overstepped its bounds in collecting information on U.S. citizens. There are already bipartisan efforts in Congress to rein in the programs and increase oversight of the intelligence agencies.

The declassification of documents also follows President Obama's call on Clapper in June to release more information about U.S. surveillance programs in response to public outcry, triggered by former National Security Agency contractor Edward Snowden's leaking of details of previously secret intelligence gathering programs.

Some of the documents shine a harsh light on how the NSA operated.

The Foreign Intelligence Surveillance Court, authorized to oversee surveillance requests, first learned in 2011 of problems involving "upstream collection" that led to the intelligence community unlawfully scooping up thousands of emails from U.S. accounts over a three-year period. One opinion shows that the NSA reported to the FISA court in 2011 that it inadvertently collected as many as 56,000 Internet communications by Americans with no connection to terrorism.

In the strongly worded 86-page opinion, U.S. District Judge John Bates, who was then the court's chief judge, wrote that the "volume and nature of the information it has been collecting is fundamentally different from what the court had been led to believe."

Bates blasted the NSA for mishandling thousands of e-mails from Americans over those three years, and said the NSA's disclosures about its e-mail collection effort "fundamentally alters the court's understanding of the scope of the collection … and requires careful re-examination of many of the assessments and presumptions underlying prior approvals.''

Sen. Richard Blumenthal, D-Conn., said the latest revelation underscores the need for greater oversight of the intelligence community. Blumenthal has proposed legislation calling for a special advocate to represent the public's interest in the secret FISA court proceedings.

"Now, the question is how many other such unconstitutional practices occurred without the court knowing, and without a special advocate to blow the whistle?" Blumenthal said. "This highly intrusive breach highlights the need for reforming the FISA court system to assure greater respect for constitutional rights, and to ensure that the American people have faith and trust in the institutions charged with keeping us safe."